Molding apparatus



1,626,225 April 26 1927' D. J. CAMPBELL MOLDING APPARATUS Filed July 20, 1925 13 Sheets-Sheel'.- -1

Dono J. Gompba D. .1.y CAMPBELL April 26, 1927. 1,626,225

MOLDING APPARATUS Filed July 20, 1925. 13 Sheets-Sheet 5 mgm Dom lfmmpb MOLDING APPARATUS Filed July 2o) 1925 13 Sheets-Sheet 4 l 'Y Mm 9 Aprl 26 1927. 1,626,225

D. J. CAMPBELL MOLDING APPARATUS Filed July 2o, 1925 13 sheets-sheet 5 Mm Dom S. Gompy April 26 1927. 1,626,225

D. J. CAMPBELL MOLDING APPARATUS Filed July 20. 1925 13 Sheets-Sheet 6 Mq. Donc E. cxmpbe April ze. 1927. 1,626,225

D. J. CAMPBELL y MOLDING APPARATUS Filed July 20, 1925 13 Sheets-Sheet '7 ln uanor Donc 5. Gum ab e April 26 1927. 1,626,225

- D. J. CAMPBELL MOLDING APPARATUS Filed July 20, 1925 13 Sheets-Sheet 8 Dwenor Donm ompbe April 26 1927. l1,626,225

v A .D. J; CAMPBELL -MQLD'ING APPARATUS Filed July 20, 1925 13 Sheets-Sheet 1Q April 26.1927. 1,626,225

D. J. CAMPBELL MoLDING yAI-#mumws Filed July 2o, 1925 1s sheets-sheet 11 A y f 101g l l 1 f Lnuenor Dom Q Gompbe 1,626,225 APfll 26 1927' D. J. CAMPBELL 4 MOLDING APPARATUS Filed July 20. 1925 13 Sheets-Sheet 12 ,L 1,62,2 April 26 1927.. l D. J. CAMPBELL 6 25 MOLDING APPARATUS Filed July 2o, 1925 1s sheets-sheet 1s Patented Apr. 25, 1927..`

DONALD J. CAMPBELL, OF MSKEGON, MICHIGAN.

i MoLniivs APPARATUS.

Appiication mea .my 20, 1925. seriaiNo. 44,733.

This invention relates to molding apparatus. tis a primary object and purpose of the present invention to provide a molding apparatus wherein the sand in a flask around and over a pattern may be jolted so as to condense the sand in the mold to a desired density, particular y in the lower portions of the flask, after which the sand within the flask may be subjected to a squeezing operation to properly condense the sand in the upper portions of the flask, Ytollowed by an elevation of the iiask with the mold therein while the pattern remains in lower position thus drawing mold trom the pattern7 all ot theseoperations to be performed through pneumatic agencies readily controlled by a single operator through the mere turning of valves which direct and control the passage ot compressed air to the mechanisms at the proper, places tor efi'ecting the various jolting, squeezing und pattern drawing operations. Vrllhe invention is capable ot many embodiments one of which is fully set forth in detail in the accompanying drawings. showing a vconstruct-ion hy means of which the operations stated are eiiected in practical and etlicent manner.v as will spear as understanding ot the invention is had trom'the following iption taken in connection-'with said drawings, in which.

Fig. 1 is a front apparatus made in accordance withmy Vinv ion.

rig. is a side elevation thereof, some being broken away and others shownv l section toi' a better disclosure of the conn ruction Fig.' a vertical section taken through the squeezing head and the mechanism for operating the saine.

F il is a fragmentary plan view of the construction shown in Fig. 3 with the squeezing head in operative position.

Fig. 5 is a vertical sect-ion through the air cylinder used to operate said squeezing head.

G is a fragmentary vertical section tz'iken through the molding apparatus from front to rear. I

Fig. 'T a fragmentary enlarged view of a portion of the apparatus relating to the pattern drawing, and showing the same as elevationv ot a molding it appears during such operation of' pattern drawing.

Fig. 8 is a horizontal section throughfthe moldnO' apparatus.

Fig. 9 is an enla through the molding plane at right angles rged vertical section apparatus taken in a to the section shown in F ig. @,fshowing the mechanism in lower position.

Fig. 10 is a view similar to that shown in Fig. 9 illustrating the position of the parts during the squeezing operation.

Fig. 11 is a view similar to Figs. 9 and 10 illustrating the parts of the mechanism in a difl'erent position or that -whichthey take when the mold is elevated above and away from the pattern.

Fig. 13.

Fig. 13 is a ragm eiitary enlarged liorif zontal sectionY through the automatic air Y control mechanism us jolting operation.

ed in Vperforming the Fig. 14 is a fragmentary horizontal section taken through one of vt-he valves shown lin Fi g. 18 but ata lower plane.

Fig. 15 is a fragmentary vertical section on t-he plane of line 1 5 15 of rig. is.

'ld-ign 16 is an .enlarged vertical section through the rvalve n Fig.A 13.

Fig. 1?

iechanisms shown in is a fragmentary vertical section taken .substantially on the plane of line 17-17 orn Fig. 13..

Fig. 18 isa horizon 18-18 ot Fig. 16.

tal section on the line Fig. 19 is a horizontal section through the control valve assembly manually operable so as to direct compressed air7 and showing the valves in the posi for the jolting operation. Fig. 20 is an enlarged tion that they occupy front elevation of' the control valve assembly Fig. 21 is a view similar to Fig. 19 indicating the position oi the valves when the squeezing head is turned to voperative position.

Fi 22 is a view similar to Fig. 21 show- Fig. 2S a view similar to Figs. 21 and ggg 1,62

22, the valves being in the position to which they are moved ior the pattern drawing operation.

l? ig. 24- is a fragmentary vertical section showing a modilied 'form oli construction embodying the invent-ion, and

TEig. 25 is a fragmentary horizontal section on the plane ot line ot Fig. 24.

Like reference characters releer to like parts in the different` figures of the drawings.

In the construct-ion of the apparatus a base 1 is provided formed from cast metal 'from which a short vertical. cylinder 2 extends upwardly which is then enlarged in diameter to make the larger cylinder 3, there being a horizontal connecting bottom el between the lower end ot the cylinder 3 and the upper end ot the cylinder 2. rllhese cylinders with the bottom e are cast integral with the base 1. At diametrically opposed points near the upper end of the cylinder 3 lugs 5 extend outwardly, each ot which has a vertical opening therethrough receiving a bushing 6 as shown. At each end ot the base l other cylinders .7 are cast and extend vertically and between the cylinders 7, 2 and 3 reinforcing ribs 8, integrally cast therewith, are interposed.

lV'ithin the cylinder 3 a piston or ram 9 is mounted, being equipped with suitable packing rings near its lower end, from which a smaller piston 1() extends downwardly adapted to be received Within the smaller cylinder 2. An annular ring 11 oi'.l hardened material is carried on the bottom Ll of the larger cylinder against which the lower end of the piston 9 may strike in its downwardA movement; and around the smaller piston 10 near the upper end ot the cylinder 2 a suitable packing 12 is secured in place to guard against the escape of compressed air.

The upper end ot the piston 9 is closed by a head 13 from which a short integral post 14 extends upwardly with which a table 15 is cast, the saine extending outward beyond the limits of the head 13. 'lwo rods 16 are connected to and depend from the table 15 passing through the bushing 6, and at their lower ends are equip )ed with heads 17 larger in diameter than the openings through the bushings. The table 15 is de- .signed to carry a pattern 18 around which the mold is to be made. Above the table 15 a second table 19 is located having an opening therein which freely passes the pattern, portions ot the table 19 extending over the table 15 so that on elevation or said table 15 the table 19 is moved therewith. Said table 19 at opposite ends thereof is formed with downwardly extending sleeves 20, each of which passes over the upper end oit a hollow piston 21 the lower end or" which is received in the adjacent cylinder 7 easesv directly beneath the sleeve 20. Said pistons 21 a short distance above the upper ends of the cylinders 7 are formed with an annular outwardly extending ilange 22 and each in one side thereof is provided with a vertical slot 23 cut through to the inner space within the cylinder, while in the opposite side at a higher level a second slot 23d is cut, as shown in Figs. 9, 10 and 11. A collar 24 is fixed within each sleeve 20 around the upper end ot each piston 21 a short distance above the flange 22. A lever 25 is pivotally mounted between its ends on a pin 26 extending across each hollow piston 2l, the lower end of the lever being received within the slot 23 and normally bearing against the inner side of the piston 21, being pressed thereagainst by a spring 27 as shown. The upper end or each lever 25 is provided with a hook or dog which, on elevation of the pistons 21 in the cylinders a ends ott the levers 25 pass above the upper ends of the cylinders, will be received in a recess cut on the inside ot the .sleeve 20 above the collar 24:. `While the levers 25 at their lower ends are within the cylinders 7, however, the hooked upper ends ot the levers are held to inner position and do not engage with and above said collars strippingl plate 28 is located above the table 19, resting thereon. rllhe stripping plate has an opening therethrough tor the passage of the pattern and also serves as a support for the llaslr 29 which is located on the same around the pattern and is distance suliicient that the lower clamped thereto by the means ot the usual lclamps 39. lilith the parts in the position shown in Fig. 9 the iasli is adapted to receive sand which may be placed therein in any desired manner.

l squeezing head 31 carried at the ends of two screws 32 is 4dapted at limes to be brought directly over the flash and patteri rlhe screws 32 pass upwardly through the ends ot' arms 33 and may be adjusted to ditierent posit-ions and held in such'positions by means of the nuts 3i, one located above and the other below the end ot each arm 33. rEhe arms 33 at their inner ends are connected by a. sleeve 35 and are mount ed for pivotal movement on a pin 35 which passes horizontally through the arms and sleeve and at its ends has a bearing` in the upper ends ot the sides 37 of a casting provided tor the support of the squeezing head. This casting in. addition to the sides 3"? includes a base 38 and a partial vertical side 39 which lies against the cylinder casting previously described, as best shown in Fig. 2.

Each of th arms 33 is Yformed with a rearwardly extending wing or vane l0 which in edect iorms the second arm ot bell crank lever. rl`hese vanes are provided with enlarged bearings 41 at their ends. A link 42 at one end passes between the bearings 41 and a pivot pin 43 passes through said bearings and end of the link The opposite end ot the link 42 is pivotally connected at 44 with one end of a member 45 which at its opposite end is pivotally mounted on a pin 46 extending between the sides 37 ot the squeezing head support. An air cylinder is positioned substantially vertically below the member 45 and is mounted for swinging movement at its lower end on a pivot pin 48 carried by the base 48 ot the support. Nithin this cylinder a piston 49 is located, a piston rod 50 extending therefrom and passing through the upper end of the cylinder and having pivotal connection to the member 45 between its ends. Air carrying pipes 52 and lead to the upper and lower ends oi the cylinder 4T above and below the piston 49, respectively. 'It is evident that onintroducing compressed air into the cylinder through the lower pipe 53, piston 49 is elevated, thereby turning the squeezing head from the position shown in Fig. 3 to that shown in 2 while on reversal of this operation or introducing compressed air through the pipe 52 into the cylinder above the piston 49 the squeezing head is moved back from the position shown in Fig. 2 to that shown in F ig. 3.

T he movement of the squeezing head troni inoperative to operative position is stopped by the engagement of the hea-d k54 eta bolt carried on an arm 55 projecting trom the sleeve striking against an abutment made by the part 56, shown in Fig. 3, which is iixedly connected with the side 37 of the support. This stopping at a. desired position is also effected by the engagement or the cross bar 45A of the member with the link 42, as shown in Fig.

At the front side oi' the molding appa ratus and near its lower end the bottoni or the lower end of the cylinder 3 is thickened and made integral with the base 1,. as indicated at 4a in Fig. 13, the space being completely filled at this point. A valve carrying member 57 is located against the part 4a at its front side and bolted thereto, it being formed with an inwardly extending cylindrical projection 58 which extends partly into a cylindrical opening bored into the part 41 (see Figs. 12 and 13). This projection 58 is formed with a cylindrical opening therethrough and to the outside or the valve carrying member 57 in which a cylinder 59 is mounted, the outer end thereof ing reduced in size as indicated at 60 and at its extreme outer end squared for the ready attachment oi a wrench, and a packing gland 61 passes over the reduced portion 6i) and is screwed into the cylindrical opening in the member 57, suitable packing heing disposed between the cylinder 59 and the gland. At its inner end the cylinder 59 is enlarged invdiameter to make a head 62 which lits the cylindrical boring beyond the projection 58. An annular groove 6:3 is made around the hea-d 62 between its ends and nearer the outer than the inner end thereof. Likewise an annular groove 64 is cut in the casting 57 around the outer end portion of the cylinder 59. Cylinder 59 is at a point such that communication may be had between the passage 65 and the annular groove orrecess 63. A` single horizontal opening 69 is bored through. the head 62 rom its inner end to the groove 63 and a plurality of'openings 70 ot the saine diameter as the opening 69 are made through the part 4'L1 at the inner end o1 the cylindrical recess in which the projection 58 and the heat 62 are received. It is evident that by turning the cylinder 59 to diierent positions the opening 69 may be'made to register with any one oi the openings 70, which openings .70 are in different vertical planes.y rEhe purpose ot this will later'appear. leihen once adjusted to a desired position the cylinder 59 is held in such position by ar set screw, vas shown in Fig. 12.

At one side of the cylinder 59 and mount ed in the valve carryingmember 5'? is a tapered valve 71 havingy a horizontal passage T2 diametrica-lly therethrough in Yits upper portion which, when the vaire is turned'to one position, aligns with an eifhaust opening 73 made in the member 'Y and at' the at 74.

opposite side oi Ythe valve, 'indicated in alignment therewithfwhich joins with a passage T5 bored a'distance into the part 4v and t ience turned upwardly, `as indicated at "5, ma ring communication with +1 j mj et1"'.js1- .pnle Lne owei tnt oi ne .nger cy mari o,

`whereby when the .valve 71 is in the posi tion shown in 13, the will have 'tree passagev from below the larger piston 9 to the outside. passage 76 ifs-,made trom the annular groove or recess 64 to the valve sol that when the valjve is turned to a position at right angles to that shown in Fig. 13 there is free communication between the lower end oiPA the larger cylinder 3 and said recess 64. t second passage 7T Vis interposed between the lower portion oia the valve and the annular recess 64 (see Fig. 16) the passages 76 and T7 b'eingseparated by a h rizental partition 78. ln the lower portion ot the 'salve 'Il an opening 79 oit the form shown in Fig. 14 is continuationr of said exhaust opening y lid inade such that when the vavo is properly positioned, as shown in Fig. 111, there is tree communication through the valve between the recess and a comiiiunicating opening S0 made in the casing 5.7 which pas sage is turned downwardly as indicated at 80n and communicates with another poi'- tion or chamber in the valve casing which will later be described.

A stein 81 extends downwardly trom valve 71 and adjacent its loweiI end carries a` disk 82, between which and the lower end ot the valve a coiled spring 88 under pressure is located holding the valve tightly in place. At the lower end ot the stein Si an arin Sei is attached to which a connecting rod, as will later appear, is coir ected iter operation of the valve to turn the saine to different positions.

At the opposite side ol2 the cylindrical member 59 in the valve casing member 5T a vertical cylindrical opening S5 is made, closed at its lower end by a solid screw plug and at its upper end by a screw plug 30 which has a central vent opening` 8'? therethroal T",'Yilithiii the cylindrical opening S5 a. cylindrical valve y same adjacent its, upper end being formed with an annular groove 8 aroundit. The valve 88 is normally held in lower position against the lower plug by means of a relatively light coiled spring 90 which is interposed between the upper end of the valve and the upper plug Sti. ln the lower position ot' the valve, as shown i Fig. 10. 1he groove S9 therein with a pipe 91 tered into a side oi? the valve casing 57 which is adapted to carry compressed it being evident that the air passes into and fills the groove. TTThilo tie per position ot the valve an outlet pipe i for the exhaust ot air is uncovered, tir saine being completely closed when the valve is in lower position. Tow ports 93 anc 94, the former being located above. the latter and the latter being in direct alignment with an elongated passage in the part -la leading to the lower end or the cylinder 2 and both communicating withV said passage 95, are mad-e in the valve casing member 57 in the side theieotl directly opposite the eX- haust pipe 92. lVheii the valve is in lower position the port 93 is in conjunction with the annular groove 89 in the valve, it being evident that air passing inwardly ifrom the pipe 91 into such annular groove or recess passes thence through the port 93 which is connected with the passage 95 and coinpressed air is carried to and below the downwardly projectine` small piston 10 at the lower end of the larger piston 3; and that when the valve is in upper position as shown in Fig. 17 air beneath said smaller piston 10 may pass freely outward through theY passage 95 and port 94 to the exhaust 85% is mounted. the

ceases pipe 99.. liroin the lower end ot the cylindrical opening 85 ar passage 96 is made in the vali/"e housing 5T, it being in communication with the downwardly extending branch 80fl'o'l the passage 80 previously described as being at times in communication with the passage 79 through valve 71, as shown in Fig. 14.

it the itiont ot the apparatus and towardA one side tlieieoi" the manual control mechanism of the apparatus is located. In its construction a vertical supporting post 97 is used, at the upper endY ot which a valve housing or casing 9S is permanently secured, into the rear side ot which a pipe 99 leads. rllhe pipe 99' is connected with any suitable tank or other source of compressed air. The casing or housing 98 has passages 100, 101 and 102 therein tor the conduction of the compressed air. rlhe two passages 100 and 101 lead in opposite directions and each entends to the end or the casing terminating in outlet or exhaust openings 100a and 1,01, while the passage 102, disposed at right angles to the passages 100 and 101, extends to J'he front side oit the casing and terminates in an exhaust outlet 10%.

i valve 10S is rotatably mounted in the 101, being positioned vertically and jf 4'* '-1'. i 'iti r1 *.1 u c is tippeA ent equipped miti a liant e a ioi' manually turning to dilierentv positions.

la pipe 91"L leads from the rear side oi the casing 98 and connects with the air pipe 91 previo y described. 1n one position ot the valve 103, as shown in Fig. 19, there is a tree passage ot compressed air iirom the pipe 99 through the passage 101 to said pipe 91 through the connecting pipe 91a. ln another position of the valve, shown in Fig. Q3, ther is a tree outward passage et the air through the pipe 91 and its connecting pipe 91a and through the exhaust outlet 1011. In other positions ot the valve, as shown in Figs. 21 and 22, there is no passage ot air by said valve 103.

The valve 103 equipped with a lower rod extension 105 which entends below the casing 98 and is held tightly in place by a spring 106 in the saine manner that valve 71 is maintained in tight ei'igagen'ient. At the lower end ot the rod 105 an arm 107 is secured between which and the arin 84 on the stein 81 otl valve 'T1 a connecting rod 108 is interposed, whereby on manual operation oi the handle 104i to turn valve 103 the valve 71 is also turned.

At the iront of the casing 98 directly op posite the point ot attachment ot the gips 91, a pipe 109 is connected, the saine leading downwardly and thence to one side to kthe mechanism which, as will be later described, controls the operation ot drawing the mold from the pattern. 1t is evident from an examination ot 19 and 23 that on turning the valve 103 to the position iio shown in Fig. 19 there is an exhaust ci air outward through the exhaust Outlet 101, and when in the other position shown in Fig. 28 there is free passage ot air trono the main supply pipe 99 to said pipe 109.

ln the passage 100 a valve 110 is located constructed similar to the valve 108 except that in one side only is a groove made tor the passage ot air. A. pipe 9 1" connects the pipe 91 with the casing 98 so as to be associated with the valve 110, whereby when said valve is turned to the position shown in Fig. 22 air from the main air supply pipe 99 is carried through the connecting pipe 91b to the pipe 91. ln the positions shown in Figs. 19 and 21 this valve is inoperative to produce any result except lclose the end ot' the passage 100, while in the position shown in 28 the passage 100 is closed and a passage made ior the exhaust ot air from the pipe 91 through the exhaust outlet at 100?. This valve is manually operable by handle 111 located above thecasing 98 and is likewise held in place by a spring `112 (see Fig. 20).

ln the passage 102 a like valve 118 is rotatably VmountedV adapted to be operated by a handle 114- and held in position by a spring'y 115 (see Fig. 20). 'The pipes 52 and 58 which are associated with the cylinder' 417 tor moving the squeezing head to operativeand inoperative position lead to the casing 98 at opposite sides, thel valve 118 eing interposed between them. r1`his valve, by movement to differentpositions, may direct the air to one O the pipes 52 with an exhaust outward through the pipe' 58,01i may reverse this direction of air so as to pass to the pipe 58 with an exhaust outward from the pipe 52. In Figs. 21 and 22 the air is shown as passing into the pipe 58 and exhausting outward yfrom, pipe 52, while in Figs. 19 and 28 the opposite takes place.

On the base 88 of the support for the squeezing head closed housing is located comprising an upper portion 116 with abettom closure plate 117. The pipe 109, previously described, leads to the upper end of this housing` and when air is directed-into said pipe 109 it is carried into the housing and above a piston 118 mounted therein. This piston has a piston rod 119 which extends upwardly through a stutling-box Vtixture 120, being equipped with nuts 121 at its upper end which may be adjusted' to ditterent positions on the rod. In practice these nuts and the projecting enfl ot the'rod are covered by a metal cap 122, Below the piston 118 the casing is filled with oil and a strong coiled spring 120 is interposed between the lower side of the piston and the bottom 11'? ot' the housing, the tendency Otg which is to force the piston upwardly. An outlet 124 leads trom the bottom 117 of the housing with which two branch pipes 125 are connected, one leading to the low-er vend of each oit the cylinders '4"'. lt is clear that on the passage ot compressed air into the housing above the piston 118 and the downward movement ot the pistou caused thereby, the oil is forced out ofthe housing through pipes 12ointo the cylinders 7 and below the elongated pistons 21 therein, elevating said pistons and the table 19 carried at their upper ends with a consequent elevation oi' the stripping plate 28 and the fiask and the mold within the tlaslr, and when the air is'fpermitted to escape troni this housing spring 128 acting to elevate the piston 118 combined with the weightot the table 19 and the pistons 21 forces the oil baclr into the housing. rllhe height to whichv the table 19, stripping plate 28 and lflask will be elevated is governed by the position of the nuts 121 on the rod 119 yas the piston 118 can be movedl downwardly only the extent permitted by the nuts when they engage against the itting 120. l

AOperation: With the part-s of the inachine in the position shown in Fig. 9, but with the squeezing headturned back to inoperativeV position, sand may be placed in the flask 29 in any desired manner, it being evident, as shown in Fig. 1, that the table 19 is formed with downwardly extending sides 19n which serve to protect the cylinders Y and pistons trom sand entrance. When the flask has been filled with sand or during its lilling it is subjected to a jolting operation. ln'suchfoperation the valve 110 is in inoperative positiointhe valve 108 is turned so as to direct the compressed air through passage 101 and into the pipe 91 through the pipe connection 91a, while .valve 118 is turned so that compressed air is directedinto the cylinder 17 through the upper pipe 52 moving the squeezing head back and holding it in inoperativer position, the air in the cylinder below the piston 49 being forced outwardly through the pipe 58 and past the valve 118, the position ot the valves being that shown in Fig. 19.f

rEhe air passing through Vthe pipe91 enters in the annular' recess 89 varound the valve 88 see Fig. 16) and thence through the port 98 to the passage 95 and under the smaller piston 10, elevating thispiston and the attached piston 8 and causingthe tables and flask to be elevated. When the valve 108 isturned to the position shown in Fig. 19 valve 71 is also turned to the position shown in Fig. 18, whereby there is a free passage to the larger cylinder 8 underneath the larger piston 9v from the outside.v At the saine` time the passage 7 9 in the valve 71 is turned to the position shown in Fig. 14 making a :tree communication between the passage 65 in the member 59 and the lower part of the-chamber 85 below the valve 88. The pistons 8 and 9 are elevated until the passage 70 is unp covered, whereupon the compressed air passes through the passages and 69, the opening 68, the passage 65, the opening 66, into the annular groove (34, whence it is carried through the passage 77, the opening 79 through the valve 71 and the passage 8O and 96 to below the cylindrical valve 38, thereby forcing the same upward against the spring 90, closing the port 93, opening port 94 and closing the end of the air supply pipe 91, whereupon the air within the smaller' cylinder 2 passes freely outward through the passage 95, port 94 and exhaust pipe 92. The pistons or rams 9 and 3 :tollow by gravity when this occurs andair which is underneath the larger piston 9 passes outwardly through the passages 75, 74, 72 and 73, as shown in Fig. 13. The piston 9 drops until it stri-kes against the hardened vring 11 -thereby jarring or jolting the mechanism and causing the sand to condense in the mold.

The v-alve at 83 moves downwardly'. by gravity and under the force ot the springas the air pressure under said valve decreases with lthe escape of the compressed air through the exhaust pipe 92, and as soon as it reaches its lower position again uncovering the port 93 and the entrance for compressed air through the pipe 91, the operation w-ill be repeated. Accordingly, with the valves in the position shown in Fig. 19 ythe cylinders 9 and 10 are elevated and then dropped repeatedly and a successive series of jolts given to the flask which has the effect or" condensing the sand in the flask, particularly at the lower portion thereof. 1t is evident that the extent ot the elevation of the pistons and attached parts is goif'erned by the position ol" the passage 69 in the head 62 relative to the particular port opening 70 with which it is in alignment. That is, the pistons 9 and 10 are elevated a greater or less extent dependent upon the height that the port opening' 69 has, and this can be changed and adjusted by turning the member 59 to different positions to bring the passage 69 in alignment with the several openings 70 which are at varying heights.

The jolting of the sand in the tlask may lie-carried to any desired degree and after it has been suiiiciently jolted and condensed the next operation is to move the squeezing head to position `over the flask. This is accomplished by turning the valves to the position shown in Fig. 21, that is, the valve 103 is turned to inoperativevposition simultaneously turning the valve 71 with it so as to render the pasfage 79 ineffective and join `passage 72 with the passages 76 and 74. Valve 11() remains unchanged but valve 113 is moved so as `to reverse the flow Vof the compressed air from the upper pipe 52 to the lower pipe 53 leading to the cylinder 47. 'When this occurs the air passing through the lower pipe 53 forces piston Atl-upwardly and the air above the piston passes outwardly through the lpipe 52. The squeezing head is thence moved from its inoperative position shown in Fig. 3 to its squeezing operative position shown in Fig. 2.

rllhe following step of operation consists in an elevation of the iask so as to bring the sand therein against the squeezing head 31. This is eiiected by turning the valve 110 from its inoperative position, shown in Fig. 21, to the position shown in Fig. 22, the squeezing head being' held by the force ot compressed air in operative position while the compressed air from the pipe 99 passes by the valve 110 through the pipe 91 and thence through the annular groove 39 in valve 38, and port 93, passage to underneath the piston 10. This causes an elevation of the pistons, tables and flask so as to squeeze the sand in the upper portion ot the flask against the under side ot the squeezing head 31, as shown in Fig. 10. During the lirst portion or" the operation ot the pistons the elevation of the cylinders is etl'ected only by the compressed air entering under the lower end of the piston 10 but after the opening 70, in alignment with the pipe 69, uncovered the compressed air passes into the passage 65, thence through the opening 66 into the annular groove 64, 'thence through the passage 76, and the passage 72, in val-ve 71, to the passage 74, being carried therefrom through the passages 75 and 7 5n to the larger' cylinder below the larger piston 9. it is evident that the valve 71 has been lturned so that the passage 72 aligns with the passage 7 6 permitting the air to pass through the passage 7 5. After the squeezing operation has been edected and the sand squeezed to the proper density the valve is turned to the position shown in Fig. 23 and the air escapes from the cylinders by a reverse movement of the air through the passages described, that is, until the opening` 70 is again covered by the smaller piston 10 after which what air remains below the pistons is trapped against escape, making an air cushion for the mechanism and insuring against any abrupt dropping or jolting of the larger piston 9 against the hardenedV ring 11, which jolting might have the effect ot'injuring the completed mold which has just been completed by the squeezing process.

After the squeezing process 4has been comileted and valve 110 has been turned to the position shown in Fig. 23 to permit the lowering of the pistons and attached parts, the valve 113 is changed in position so as to reverse the low of air through 'the pipes and 53 and move the squeezing' head to inoperative position. Also the valve 113 given a further quarter turn from the positions shown in Figs. 21 and 22 thereby directing the compressed air through the pipe 109 to the housing '116. rlhis causes the piston 118 to be :torced downwardly until stopped by the nuts 121,l strilringagainst the iifrture 120, the oil within the housing being forced outwardly through the two branch pipes 125 to the lower endet cylinders 7 below the pistons 21 which are elevated, as shown in Fig. 11. 1lilith this elevation Vthe table 19 and stripping plate with the flask and in old above the stripping plate are elevated7 thel pattern reina' no; in lower position thereby etliecting a drawing oi' the pattern troni the mold which.v with its tiasli.7 may be remoi'ed Vtroni the plate and replaced by a new flask. 'ihe valve 103 inaythen be tiiriied to the position shown in Fig. 19 allowing the compressed. air to erihaustoutwardly throughV the pipe 102 with a return or" the parts to lower position. The latch levers 25 when their lower ends have passed abovek the upper ends of the cylinders 'i' engage at their upper en-ds with the rings 2i against which the flanges 22 on the pistons 21 bearduring the pattern drawing operation and on the return of the parts to lower position7 the saine return together, the levers 25 being` disengaged when their lower ends enter the u oper ends of the cviinders 7. The cycle oit operationsY may now be repeated for a new mold starting again with the jolting andit is evident that the air which has been trapped below the cylinders has no detrimental effect with respect to the first iolting` operation. In fact it has the beneiicial eiect of not requiring as much air for the elevation in the first jolting operation.

With this construction molds may be made, j olted andcompressed to proper density and drawn trom the patterns entirely through pneumatic agencies, Vthe Vonly other labor necessary being that ot putting the sand into the flash.V The jolting may occur during the time that the flask is being tilled with sand for the purpose of saving time in constructing molds. 1t is evident that the air required 'tor the jolting operation is kept down to a minimum byreason oit thev tact thatthe air used enters only under the end of the smaller piston 10 in the smaller cylinder 2 which lreeps the volume ot air used much lower than it it had to be entered undorneaththe whole area or" the larger pis-1 ton in addition. rilhe elevation ot the stripping plate and i'iask when thek pattern is drawn is governed by the position of theV nuts 121 on the rod 119 and insurance is also made against too far upward movement by the heads 17 on the rods 16 which permit such upward movement only until said heads come in engagement withthe lower sides ot the lugs 5. Furthermore the elevation of the piston 9 to a point above the openings 3a cannot take place, such openings dissipating the pressure or the air below Ithe pis-` ton when they are uncovered. y

The invention is capable 01"' embodiment in a variety oiC forms and it is not desired that the same be restricted to the one orm previ-V shown. ln this construction insteadot' the;

small cvlinder 2 and the downward n'o'ec- `tion 10 to the piston 9, the piston 9 is ifornied with an upwardly extending cylindrical member 10' at its lower rend which over a cylindrical projection 2 cast integral with the base 1 andthe bottom iot' the main cylinder 3.- In a wall oit the' part 1()a a tubular valve 125 is mounted in vertical'position, the same lhaf'iiig three holes 12T in its sides at vdifferent positions in the ieight thereof which are adapted, when the valve is turned to proper position, to come into alignment with the three passages 127a made from the valve to the inner' side or' the part 10a. rlhe tubular valve in this way may be used to exhaust the air through an one oit the passages 127a which is in conjunction with'an opening 1277 this controlling the height to which the cylinder 9 risesdiiring the bumping operation. A casing 128 is iixed to the lower end ot the cylinder l throughthe lower portion of which a horizontal passage 129 is made, t-he same joining' with a passage 130 inade through the base 1 and the ,projection 2 to the upper end thereof. Air is ycarried into said passages through the'pipe 91. vThere is a second passage 131 leading to below the main piston 9a andy preferably in alignment with .the opening in the tubular valve 126 at its lower end. The outer end of the passage 131 aligns with the passages 132 through the casing 128 into the outer end ot which the pipe 92 is secured. A relatively large cylindrical opening is bored into `the upper end ot' the casing 128 across the passage 132 and is closed at its upper' end by a plug, a piston 13eL being mounted in the opening 133 from which a rod 135 extends upwardly through the plug., The piston isnormally held in upper position by acoiled spring 136.

l/Vhen the air is carried through the pipe 91 to the cylindrical portion 10, cylinder 9 is lifted until the passage 127a which oins with lthe opening 127 in the valve 126is uncovered, whereuponthe air escapes there-A hrough permittingcylinder 9 to tali and iolt the flask carriedv thereon. VVBy* moving the piston 134i downwardly across the passage V132 this air cannot escape andthe cylin- 

